lines on display after lcd replacement

I am working on replacing the digitizer on my iPad 4. I believe I reconnected everything properly, except when I power it on to test it before reassembly all I can get out of the display are a series on horizontal lines. I tried unplugging and reconnecting the cable numerous times to no avail, I noticed when it is laying in the bezel it Almost seems right. I'm wondering if the metal contacts on the middle of ribbon cable, as in the plates not where the cable terminates, serve a purpose or have I possibly done some damage. Thanks for your help